Q47 · UPSC Prelims 2026 · Set A · Science and Technology

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Which of the following statements with regard to drone swarms is/are correct?1.They use Terahertz band of frequency to communicate with the command centre.2.Individual drones in the swarm can communicate with other drones in the swarm.3.GPS Spoofing is a commonly used technique to counter drone swarm attack. Select the answer using the code given below:

Page facts
Exam
Union Public Service Commission — Civil Services Examination (UPSC)
Board
UPSC
Stage
Prelims
Year
2026
Paper
UPSC Prelims — Prelims General Studies Paper I (General Studies)
Booklet
Set A
Question
Q47
Topic
Science and Technology
Syllabus
Science, technology, space, defence, IT — Prelims GS Paper I.
A 1 only
B 2 and 3 only
C 1 and 2 only
D 1, 2 and 3

Correct answer: (b) 2 and 3 only

Explanation

  1. A

    1 only

    1 only: This option is incorrect because drone swarms primarily use robust ad-hoc wireless networks, cellular networks, or secure military RF bands (such as UHF/VHF or C-band) for swarm coordination rather than the Terahertz band, which is still largely experimental for long-range mobile drone tactical communications.

  2. B

    2 and 3 only

    2 and 3 only. Statement 2 is correct because swarm intelligence relies heavily on decentralized peer-to-peer (P2P) communication between individual drones to maintain formation and avoid collisions without centralized control. Statement 3 is correct because GPS spoofing—overriding true satellite signals with false ones—is a primary countermeasure to disrupt the navigation of autonomous drone swarms.

  3. C

    1 and 2 only

    1 and 2 only: This option is incorrect because statement 1 is factually wrong regarding the use of Terahertz frequencies for standard operational drone swarm command-and-control links.

  4. D

    1, 2 and 3

    1, 2 and 3: This option is incorrect because it includes statement 1, which incorrectly attributes Terahertz communication as the standard frequency band for drone swarms. Summary. Official key is (b). Drone swarms operate on decentralized inter-drone communication networks rather than experimental Terahertz frequencies, and they remain vulnerable to GPS spoofing countermeasures.

Summary. Official key is (b). Drone swarms operate on decentralized inter-drone communication networks rather than experimental Terahertz frequencies, and they remain vulnerable to GPS spoofing countermeasures.

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